The link you provided is for the company, "Dynamic Mounting". They make mounts that allow you pull the TV down to a lower level. Have to be careful in reading their suggestions as some might be based on mounting height vs pull-down height.
In any case, I installed a Dynamic Mount above our family room fireplace so we can pull the screen down to eye level when watching movies. For "regular TV" viewing like the news or whatnot we just leave up high. Fireplaces are not ideal for TV mounting locations so the Dynamic Mount is a great solution.
